1. Field of the Invention
The present invention relates to the field of enhancing milk production in mammals. More particularly, it concerns pharmaceutical compositions and methods of using said compositions in a manner effective to induce milk production in previously non-lactating animals.
2. Technical Problem Addressed by the Invention
Commercial raising of cattle for dairy production requires proper management. In addition to the various husbandry concerns such as herd health and nutrition, a critical management area for economic survival of any cattle operation, is the breeding management of the cows. In the case of dairy cows, the cows will not produce milk unless they have a calf, which is again dependent upon successful breeding management.
The timing of breeding and breeding intervals generally have great economic significance in dairy operations. Dairy cows are managed intensively and there are costs associated with breeding the cow, how long it takes each cow to become pregnant, as well as associated labor costs; economics of a dairy make it important to both minimize the amount of time a dairy cow is not pregnant and yet still have a high probability of the cow becoming pregnant.
If a cow is successfully bred, she will become pregnant for approximately 280 days. Dairy cows are managed such that they are ideally bred and become pregnant again 45 to 60 days after calving.
It is estimated that for every day past a set goal date that a cow remains non-pregnant or open, there is an economic loss of between $1.00-$3.00 per day. For an average sized dairy herd that is between 200 to 1,000 cows, if the 24 hours during which the cow should be bred is missed for each cow, this represents an economic loss of $4,200.00 to $21,000.00 annually. Often cows are not successfully bred for as many as 3 estrous cycles, due to infertility, infections and semen-related problems. If one half of the cows in a herd of 200 to 1,000 is not impregnated for 3 cycles, the estimated economic loss increases to $6,300.00 to $31,500.00 annually. These projections of economic loss to the producer demonstrate the critical importance of the cow spending the majority of each year producing milk.
Annually 1 million dairy cows are culled for reproductive failure. It is estimated that dairies would retain approximately half of these cows if they were lactating.
To improve the management of dairy cows and decrease the economic losses associated with the non-pregnant interval it is desirable to have additional options and management tools other than culling animals. There is an estimated cost of approximately $900.00 per animal culled for a dairy in addition to the costs incurred for days the animal is at the dairy prior to the decision to replace the animal. The option to be able to selectively use hormonally-induced lactation as a management tool, is desirable. One example of where induced lactation might be an appropriate option is with problem breeder animals of excellent genetic background.
Scientists have been attempting to induce lactation artificially in dairy cows for over 30 years. In general, the studies have involved long hormone administration with low rates of success.
The instant invention provides a method for inducing lactation in a high proportion of mammals; wherein neither the ability to induce lactation, nor the milk yield is affected by the season.